This invention relates to a gas permeable electrode of so-called BFE (Backward Feed & Exhaust) type which comprises a reaction layer and a gas permeable layer attached to each other, and is employed as an electrode for a methanol fuel cell and a secondary battery and for reducing potential of an electrolytic bath and for the like.
A conventional electrode for a methanol fuel cell and so on comprises a metal mesh, a carbon fiber cloth or the like supporting catalysts. The methanol is dissolved in a strong acid or alkali, for example sulfuric acid, to be supplied as electrolytic to be circulated therein. The constitution of this cell and the enlarged view of the portion indicated by B are shown in FIGS. 1 (a) and (b), respectively.
This electrode for the methanol fuel cell has a problem that carbon dioxide bubbles 1 produced as one of the reaction products cover the surface of catalysts 2 to result in a lowering of effectiveness of the catalysts and of electrode characteristics. The main use of the methanol fuel cell is considered to be a transportable or mobile electric source, and the circulation of the strongly corrosive electrolyte is dangerous and may lead to the corrosion of the equipment employed. Moreover, the corroded product may bring about the poisoning of the catalysts. Purification of electrolyte and water is further required to prevent the poisoning of the catalysts.